Answers

Opium poppies (Papaver somniferum) and oriental poppies (Papaver orientalis) are different plants, so it depends which one you have. I am unsure whether Papaver orientalis seeds are usable in baking.

The last time I bought poppy seeds for culinary purposes in the house the packet said it was blue poppies (bought from Chinese supermarket) but I'm fairly sure that Papaver somniferum is used for baking and you can also use Papaver rhoeas for that purpose too. I think the opiate alkaloids or at least the majority of them are in the seed casing rather than the seeds themselves.

I'm intrigued by the usage of Nigella in flatbreads - with it self-seeding more massively in my borders than the poppies, maybe I should take note!